U.S. patent application number 13/001544 was filed with the patent office on 2011-05-05 for system for the leaktight connection of valve units to respective pipes, in particular for use with combustible gases.
This patent application is currently assigned to SIT LA PRECISA S.P.A. CON SOCIO UNICO. Invention is credited to Michele Benvenuto, Marco Bucci, Davide De Iulio, Luca Peron, Stefano Zanella.
Application Number | 20110101674 13/001544 |
Document ID | / |
Family ID | 41319395 |
Filed Date | 2011-05-05 |
United States Patent
Application |
20110101674 |
Kind Code |
A1 |
Benvenuto; Michele ; et
al. |
May 5, 2011 |
SYSTEM FOR THE LEAKTIGHT CONNECTION OF VALVE UNITS TO RESPECTIVE
PIPES, IN PARTICULAR FOR USE WITH COMBUSTIBLE GASES
Abstract
A system for the leaktight connection of a valve unit to a
respective pipe, is provided. The valve unit includes a gas
through-flow section, a threaded male attachment element being
formed integrally with the valve unit and having an axial through
cavity defining the gas through-flow section, for leaktight
clamping by a pipe-fixing ring-nut connector which can be screwed
onto the male threaded portion of the attachment element. The
system includes a second leaktight connector which can be put into
operation as an alternative to the ring-nut connector. The second
connector including at least one axial retaining element which can
be releasably restrained on the valve unit in the region of the
threaded portion of the male attachment element, in a manner such
that the pipe is restrained axially relative to the valve unit.
Inventors: |
Benvenuto; Michele;
(Mogliano Veneto, IT) ; De Iulio; Davide;
(Perarolo Di Vigonza, IT) ; Peron; Luca;
(Borgoricco, IT) ; Zanella; Stefano;
(Montebelluna, IT) ; Bucci; Marco; (Monselice,
IT) |
Assignee: |
SIT LA PRECISA S.P.A. CON SOCIO
UNICO
Padova
IT
|
Family ID: |
41319395 |
Appl. No.: |
13/001544 |
Filed: |
July 3, 2009 |
PCT Filed: |
July 3, 2009 |
PCT NO: |
PCT/IT09/00295 |
371 Date: |
December 27, 2010 |
Current U.S.
Class: |
285/92 |
Current CPC
Class: |
F16L 37/1225 20130101;
F16L 19/025 20130101; F16L 19/0237 20130101; F16L 25/009
20130101 |
Class at
Publication: |
285/92 |
International
Class: |
F16L 37/12 20060101
F16L037/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 8, 2008 |
IT |
PD2008A000201 |
Claims
1. A system for the leaktight connection of a valve unit (1) to a
respective pipe (2), in particular for combustible gases, wherein
the valve unit comprises a gas through-flow section which can be
connected, with flow communication, to a respective end section of
the pipe, a threaded male attachment element (3) being formed
integrally with the valve unit and having an axial through cavity
(4) defining the gas through-flow section, the attachment element
(3) comprising, at its free end, an annular surface connectible to
a respective first type of the end of the pipe (2), clamping with
optional gas-tightness between the coupling surfaces being
achievable by a pipe-fixing ring-nut connector which can be screwed
onto the male threaded portion of the attachment element, wherein
the system comprises a second leaktight connector which can be put
into operation as an alternative to the ring-nut connector that can
be screwed onto the male attachment element, for the connection of
the valve unit to at least one second type of pipe end, the second
connector comprising: at least one first shoulder surface (5a)
which is provided in the region of that axial end of the male
attachment element (3) which extends at the end longitudinally
remote from the free end thereof, at least one second shoulder
surface (8) provided on the outer surface of the pipe (2), the
second shoulder being defined between a first portion (2a) of the
pipe that can be engaged in the central cavity of the male
attachment and a second portion (2b) which projects out of the
cavity when the pipe is housed therein, at least one third shoulder
surface (7) which is formed in the inner surface of the cavity (4)
extending axially through the male attachment element (3) and which
the free end of the pipe (2) can abut when the pipe is housed in
the cavity (4), in a corresponding operative engagement position,
at least one axial retaining element (11) which can be restrained
releasably on the valve unit (1) in the region of the threaded
portion of the male attachment element (3), the retaining element
comprising at least one first surface portion and one second
surface portion which are spaced apart axially and can abut the
first and second shoulder surfaces (5a, 8), respectively, in the
operative position of the pipe, as a result of the coupling of the
retaining element with the valve unit in a manner such that the
pipe (2) is restrained axially relative to the valve unit, against
release from the operative position, a gastight member being
provided between the outer surface of the first portion (2a) of
pipe and the surface of the cavity (4) which extends through the
attachment element (3) and can house the pipe.
2. A connection system according to claim 1 wherein the first
shoulder surface (5a) is defined in a groove (5) extending around
at least a circumferential portion of the outer surface of the male
attachment element (3) in a position between the body (1a) of the
valve unit and the threaded portion of the element (3).
3. A connection system according to claim 2 wherein the retaining
element (11) is formed as a resilient clip, the first surface
portion including a first pair of branches (12c, 13c) of the clip
which can engage the groove (5) on diametrally opposed sides
thereof, the second surface portion comprising a second pair of
branches (12d, 13d) of the clip which can abut the second shoulder
surface (8) on diametrally opposed sides of the outer surface of
the pipe.
4. A connection system according to claim 3 wherein the first pair
of branches of the clip are connected to the second pair of
branches by at least one linking portion (14) which extends axially
when the clip is mounted in the operative position on the valve
unit but which is of a size such as to extend around the threaded
portion of the male attachment element (3) without any
interference.
5. A connection system according to claim 4 wherein each branch
(12c, 13c) of the first pair and each corresponding branch (12d,
13d) of the second pair that is positioned on the same side of the
attachment element (3) are spaced apart axially, the spacing being
selected such that, when the clip is mounted on the valve unit, the
branches do not interfere with the threaded portion of the
attachment element since they are positioned at the opposite axial
ends thereof, without any interference.
6. A connection system according to claim 5 wherein each branch of
the first pair is connected to the corresponding branch of the
second pair that is disposed on the same side of the attachment
element by a connection portion that extends between the ends of
the branches remote from the ends that are located in the region of
the linking portion (14).
7. A connection system according to claim 3, wherein the branches
of each pair have a shape with a predominantly curved profile
corresponding to the profile of the outer surface of the male
attachment element (3), with radii of curvature such as to engage
in abutment with the first and second shoulder surfaces (5a, 8),
respectively.
8. A connection system according to claim 3, wherein the clip is
movable away from and towards the operative position transversely
relative to the principal axis of the male attachment element (3),
the branches of each first and second pair being capable of being
opened out resiliently, radially away from and towards the
operative position wherein the pipe (2) is clamped axially relative
to the valve unit (1).
9. A connection system according to claim 1 wherein the gastight
member comprises at least one sealing ring (10) which is housed in
a circumferential seat (9) of the first portion of the pipe (2) and
which can contact the cylindrical internal surface of the central
cavity (4) provided in the attachment element (3) for the
engagement of the pipe, that contact ensuring gas-tightness between
the surfaces that are mutually engaged in the engagement of the
pipe (2) with the valve unit (1).
Description
TECHNICAL FIELD
[0001] The present invention concerns a system for the leaktight
connection of valve units to respective pipes, according to the
characteristics mentioned in the preamble of the main claim.
TECHNOLOGICAL BACKGROUND
[0002] The invention lies particularly, but not exclusively, in the
specific field of systems for the leaktight connection of valve
units arranged for delivering combustible gas to burners of heating
apparatuses, such as boilers, fireplaces or the like.
[0003] In this field, in order to connect the valve unit to the gas
pipes, it is known to arrange in the body of the unit itself
respective threaded male attachment elements, which can be
connected to the respective pipes by pipe-fixing ring-nut means,
screwed onto the attachment in a manner such as to retain an end of
the pipe in a gas-tight manner on the body of the valve unit. A
typical solution provides for the attachment element to be provided
at its free end with a front surface which can be coupled to one
end, preferably with countersunk profile, of the corresponding
pipe, in order to ensure a gas-tight seal in the coupling of such
surfaces as a result of the clamping, by screwing, of the ring-nut
on the threaded spigot of the attachment element. An example of
such a connection system is described in Italian Patent Application
No. PD2006A000080 in the name of the Applicant.
[0004] Systems for leaktight connection, in particular between
tubular sections of pipes, are also known in which the axial
retention between the sections is obtained by the action of
resilient retaining elements, such as wire clips or similar
devices, which can be releasably connected between the tubular
sections and which act between same in order to ensure mutual
gas-tight axial clamping between the coupling tubular sections.
Such systems prove effective owing to the ease and rapidity of use,
as well as the fact that they result in structural simplifications,
in terms of overall dimensions and number of parts required for the
connection.
DESCRIPTION OF THE INVENTION
[0005] A principal aim of the invention is that of providing a
system for the leaktight connection of valve units to respective
pipes which permits gas-tight connection, on the same valve body,
to different types of pipes, and in particular which permits, as an
alternative, leaktight connection both to clamping means with
threaded ring-nut and to connecting means having releasable
resilient retaining elements, thus widening the range of possible
connections provided in the installation stages with the same valve
unit.
[0006] These and other aims which will become clearer hereinafter
are achieved by means of a system for leaktight connection produced
according to the following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Further characteristics and advantages of the invention will
become clearer from the following detailed description of a
preferred exemplary embodiment thereof, illustrated by way of
non-limiting example with reference to the appended drawings, in
which:
[0008] FIG. 1 is a perspective view of a valve unit connected to a
pipe in a leaktight manner according to the connection system of
the invention,
[0009] FIG. 2 is a perspective, exploded, view of the connection
system of the preceding Figure,
[0010] FIG. 3 is a front view of the valve unit of FIG. 1, in which
the connection system is in the coupled state,
[0011] FIG. 4 is a view in section along the line IV-IV of FIG.
3,
[0012] FIG. 5 is a view in section along the line V-V of FIG.
3,
[0013] FIG. 6 is a schematic sectional view of a valve unit
operating with the connection system of the invention, used in a
leaktight connection of known type to a pipe,
[0014] FIG. 7 is a view corresponding to that of FIG. 5 in an
alternative embodiment of the invention.
PREFERRED EXEMPLARY EMBODIMENTS OF THE INVENTION
[0015] With reference to the drawings mentioned, the reference 1
designates as a whole a valve unit, shown only partially, arranged
to be connected to a pipe 2, according to a system for leaktight
connection provided according to the present invention. The pipe
may form the supply pipe or delivery pipe for the gas relative to
the valve unit. Provision may also be made for both the supply pipe
and the delivery pipe for the gas to be arranged to be connected in
a leaktight manner to the body 1a of the valve unit by means of the
system of the invention. A description will therefore now be given
of the connection system with reference only to the pipe 2, within
the limits of the aforesaid explanation.
[0016] Said tube is connected to the valve unit in the region of an
attachment provided on the body 1a of the valve unit. Said
attachment is of the threaded engagement type and comprises a male
attachment element 3, formed integrally with the valve body 1a and
projecting axially therefrom, as shown in the drawings. More
particularly, the threaded attachment element 3 is cylindrical in
shape and has an axial cavity 4, in the form of a cylindrical
through bore, intended to place the pipe 2 in flow communication
with the gas through-flow inside the valve unit. The through cavity
4 is coaxial with the cylindrical threaded attachment 3, with X
indicating the direction of their axial extension.
[0017] The attachment element, starting from the valve body 1a,
comprises a first portion including a groove 5, extending for at
least part of its circumferential profile, and a second cylindrical
portion, in prolongation of the first portion, and on which the
external thread of the attachment is provided. At the free end of
the attachment an annular front surface 6 is defined.
[0018] In the groove 5, in a position adjacent to the threaded
portion of the attachment, a shoulder surface 5a is defined, the
function of which will become clear from the continuation of the
description.
[0019] A further radial shoulder surface, indicated by 7, is
provided inside the axial cavity 4 and is defined, in the direction
of the free end of the attachment, between a first axial part of
the cylindrical cavity 4 and a second axial part of the cavity,
adjacent to the first part and having a larger diameter than said
first part, as is clearly shown in FIGS. 4 and 5.
[0020] Correspondingly, the pipe 2 comprises in its outer
cylindrical surface, in the region of the end connectible to the
valve unit, a shoulder surface 8. The radial shoulder is defined
between a first axial pipe portion 2a, extending from the free end
of the pipe itself, and a second axial portion 2b of the pipe,
adjacent to the first portion and having a smaller diameter than
the first portion. In the first pipe portion 2a a circumferential
seat 9 is also provided, intended to house a sealing ring 10, for
example of the O-ring type, in order to ensure gas-tightness in
contact with the inner surface of the axial cavity 4, following the
connection by engagement of the pipe 2 in the cavity itself.
[0021] The connection system also comprises a retaining element,
indicated as a whole by 11, which can be restrained axially, and
releasably, on the valve body 1a, and can also itself retain the
pipe 2, in a manner secured to the valve unit and gas-tight, as
will become clear from the following description.
[0022] More particularly, the retaining element 11 is formed as a
clip made of metal sheet, for example of harmonic steel, which has
a preferred forked shape with two opposed arms 12, 13 connected to
each other at one end by a linking portion 14.
[0023] In the arm 12, a pair of opposed branches 12a, 12b are
defined, extending substantially parallel to each other and also
spaced apart. They are also connected at their free ends, on the
side remote from the linking portion 14, by a connecting crosspiece
15.
[0024] Similarly, in the arm 13 a pair of branches 13a, 13b are
defined, extending substantially parallel and spaced apart from
each other. The reference 16 indicates a corresponding connecting
crosspiece for the branches 13a, 13b. It should be noted that the
arms 12, 13 are shaped as mirror-images of each other with respect
to a central median plane of symmetry, passing perpendicularly to
the upper flat linking portion 14 of the clip.
[0025] In each of the branches 12a, 13a, which are diametrally
opposed with respect to the direction X in the stage of connection
of the clip to the valve body, a respective central portion 12c,
13c with curved profile is defined, the radius of curvature of
which is selected such that the portions are in abutment against
the shoulder 5 of the groove 5, as a result of the connection of
the clip to the valve body. Similarly, in each of the branches 12b,
13b, which are also diametrally opposed, a respective central
portion 12d, 13d with curved profile is defined, the radius of
curvature of which is selected such that the portions are in
abutment against the shoulder 8 of the pipe 2, as a result of the
connection of the clip to the valve body.
[0026] Further indicated by 15a, 16a are the respective through
openings which are defined in the arms 12, 13, by the continuous
peripheral profile delimited by the opposed branches and by the
connecting portions of same.
[0027] Provision is also made for the ends of the arms 12 and 13,
on the side remote from the upper linking portion 14, to be bent
back to diverge from each other, as illustrated in FIG. 2, so as to
facilitate the step of connection and disconnection of the clip to
and from the valve body.
[0028] The connection system of the invention provides that,
starting from the position of FIG. 2, with the parts disengaged,
with mutual axial spacing, the pipe 2 is inserted with its portion
2a into the cylindrical axial cavity 4 of the valve body. The
insertion is completed when the free end of the pipe is in abutment
against the internal shoulder 7. In this position the sealing ring
10 is in contact with the cylindrical surface of the cylindrical
cavity 4, ensuring, by means of appropriate choice of dimensions,
the gas-tight seal between the coupled cylindrical surfaces.
[0029] When the axial engagement position is completed, the clip
element 11, in a movement transverse to the axis X, is fitted onto
the attachment 3, with prior resilient opening out of the arms 12
and 13 (as a result of the interference encountered through the
presence of the cylindrical threaded portion of the attachment
itself). The movement transverse to the axis X is completed when
the portions 12c, 13c of the clip are engaged in the groove 5,
engaging in abutment against the shoulder 5a. At the same time, the
portions 12d, 13d are caused to engage the outer surface of the
pipe by abutting against the shoulder 8. The action of opposed
abutment between the shoulders 5a and 8, owing to the axial
rigidity of the clip (with an appropriate predefined axial distance
between the branches of the arms which act on the same side),
ensures the axial retention of the pipe relative to the valve body
1a, completing the leaktight connection between same.
[0030] In order to disconnect the pipe 2 from the valve unit, it is
sufficient to disconnect the resilient clip, by means of a reverse
transverse movement, until the arms are disengaged from the
respective coupled surfaces. The resilience of the arms themselves
permits the resilient opening out necessary for the withdrawal of
the clip away from the operative connection position described
above.
[0031] It should be noted that the presence of the openings 15a,
16a in the respective arms of the clip 11 allows it to be fitted
onto the threaded portion of the attachment, without interfering
with the attachment itself. As a result, the system lends itself
advantageously to being employed in valve units provided with
threaded male attachments, of the type described, the threads of
which are intended to be engaged by pipe-fixing ring-nuts, whenever
a conventional type of leaktight connection is opted for, which can
be provided as an alternative to the connection system of the
invention, the two systems being thus able to co-exist and be
employed as an alternative to each other for the same valve unit,
and in dependence on the different type of pipe selected for
connection to the valve unit, all of which widens the possibilities
of connection provided in the stage of constructional installation
of the valve unit with the corresponding pipes.
[0032] FIG. 6 illustrates schematically a conventional type of
connection in which the valve unit 1 described above is connected
in a leaktight manner to a pipe 2' which has a frontal annular end
edge 20 which can, be surface connected, by superposition, to the
front surface 6 of the attachment. For leaktight clamping of the
surfaces in contact, a respective pipe-fixing ring-nut or nut 25 is
provided, fitted onto the corresponding pipe and including an
internally threaded cylindrical seat 25a, the nut-screw of which
can be engaged by screwing on the corresponding threaded portion of
the attachment 4. The screwing action effects the axial clamping
between the surfaces 6 and 20 in mutual contact.
[0033] An optional sealing ring 31 may be interposed between the
aforesaid surfaces in order to ensure gas-tightness between the
coupled parts.
[0034] FIG. 7 (for axial symmetry only half a section is shown)
illustrates an alternative embodiment of the invention, in which
details analogous to those of the example of FIG. 5 are designated
by the same reference numerals. This variant differs principally in
that the sealing ring 10, of the O-ring type, is pre-mounted in the
axial cavity 4 of the valve body 1a, for example housed in a
suitable seat formed in the cylindrical wall of the cavity. This
permits simpler execution of the portion 2a of pipe 2, as is
clearly shown in FIG. 6. Said pipe conveniently has a pinch 2c
protruding circumferentially and which defines a circumferential
raised portion which can abut between the front surface 6 of the
attachment and the portions 12d, 13d of the clip, thus effecting
the axial clamping of the pipe 2.
[0035] It is also to be understood that the retaining element may
assume a different shape from that previously described, but in any
case such as to have at least a first and a second surface portion,
spaced apart from each other axially and which can also abut
against the shoulders 5a and 8 so as to secure and axially restrain
the parts coupled to each other. It is also understood that the
clip may be of a different material and shape, but still within the
same inventive concept which is the basis of the system
claimed.
[0036] The invention thus achieves the aims proposed, obtaining the
advantages mentioned above compared with the known solutions.
* * * * *